How do pcb circuit board handle prolonged exposure to vibration?
pcb circuit board handle prolonged exposure to vibration
The electronics industry requires devices to operate in extreme environments and conditions such as high vibration, varying temperatures, humidity and exposure to dust and other particle matter. In order for these devices to function effectively, a PCB circuit board needs to be able to withstand these extremes. This is particularly true of medical equipment and the military and defence industries, where these devices are often exposed to long periods of shock and vibration events.
The first step to ensuring that a pcb circuit board can withstand vibration is to design it with the right materials and features from the outset. It is also important to use the right design software that allows electrical and mechanical co-design, such as Altium Designer. This allows you to create a 3D mechanical model of your Printed Circuit Board and its mounting style, which will allow for optimal performance in a range of environments.
Vibrations can cause problems in the form of mechanical stress that can crack components and structural parts of the circuit board, as well as electromagnetic interference (EMI). EMI can be caused by stray currents passing through the board, which can interfere with the circuit’s functionality. In these cases, the device can be damaged by short circuits, overheating or a loss of functionality.
How do pcb circuit board handle prolonged exposure to vibration?
PCBs are designed using a variety of different materials, but the most common material is dielectric composite, with a layer of copper laminated onto and between layers of insulating resin. The dielectric composite is typically made from a phenolic or epoxy resin and a woven or non-woven fabric of glass fibers, paper or other filler. The epoxy or phenolic matrix forms the core of the circuit board, with the reinforcement acting as a flexural or torsional stiffener.
During assembly, the bare circuit board is populated with electronic components to make a functional Printed Circuit Board Assembly, or PCBA. The component leads are either inserted into holes surrounded by conductive pads on the surfaces of the PCB or fixed to lands and soldered to them with solder paste. The final step of the process is to apply a protective layer called solder mask, which covers the entire surface of the populated circuit board except for the conductive pads where components are soldered.
When a PCB is subjected to vibration, the metal traces on the surface of the circuit board will oscillate, which stresses the plating in these holes and can cause them to break or crack. This can lead to intermittent operation or even catastrophic failure of the entire circuit board. To reduce the risk of this, a simple mitigation measure is to increase the thickness of the copper traces on the circuit board. Thicker copper can dissipate more heat and reduce the chance of a hole or crack occurring. If your pcb data supports the manufacture of a thicker copper, then this can be an easy and cost-effective way to ensure that a circuit board can handle vibration and other environmental extremes.
